In one of its many last-minute environmental actions, the Bush administration has delayed a decision on a drinking water standard for the contaminant perchlorate, but issued a temporary advisory recommendation. The actions have immediate implications for at least 31 large US utilities, and may suggest looming concerns for hundreds more. There also are immediate and long-term implications for cleanups at Superfund sites.

The EPA action was blasted as "immoral" by Sen. Barbara Boxer (D-CA), chair of the Committee on Environment and Public Works, who said it delayed yet again a decision on a sufficiently protective regulatory standard. She considered the issue important enough to have it discussed during the confirmation hearing for Obama's selection for EPA Administrator, Lisa Jackson.

Perchlorate is used in rocket fuel, explosives, fireworks, and many other industrial products, and also occurs naturally in soils and deeper deposits. Contaminated sites have been found in at least 43 states. Many are on or near military sites or other federal lands, such as NASA and Dept. of Energy properties. Some critics charge that the potential liability on federal lands is influencing EPA's decision that could cost the federal government billions of dollars in cleanups. Perchlorate contamination in drinking water has been documented since at least 1957. Perchlorate has also been documented in about three-fourths of all foods the FDA has tested as part of its Total Diet Study, possibly due to absorption from fertilizer or contaminated irrigation water.

The primary health concern identified so far is perchlorate's ability to disrupt important functions of the thyroid gland, particularly in fetuses, children, and some women. The Environmental Working Group (EWG) estimated in 2006, based on a CDC report, that the population at risk includes at least 44 million women. The CDC study found that perchlorate was present in 100% of the tested people.

Perchlorate contamination has been an issue throughout the entire Bush administration, and before. After considerable study, and contrary to some of its own science that suggested adoption of a much more stringent concentration, the EPA had established, through actions in 2005 and 2006, a nonregulatory "guidance" concentration of 24.5 micrograms per liter (ug/L) for drinking water and Superfund sites. That concentration was based in large part on the conclusions of a National Academies National Research Council report issued in January 2005. It was far lower than the industry-recommended 200 ug/L, but much higher than the 1 ug/L recommended by many health and environmental advocates. Some of the health advocates' concern was due to the occurrence of perchlorate in both water and food; they felt that not enough consideration was given to multiple sources of exposure.

On Jan. 8, 2009, EPA announced that it was once again asking the National Academies to study the issue, before EPA makes a decision on whether, and how, to regulate perchlorate. Any results from such a study are unlikely for quite a while. In the meantime, EPA issued an "interim health advisory," at a concentration of 15 ug/L (or ppb). The new number applies both to drinking water and cleanup at Superfund sites. EPA's moves come on the heels of more than 32,000 comments it received after issuing an Oct. 10, 2008, preliminary regulatory determination on perchlorate, as well as critical peer-review comments it received while drafting its determination.

Using the same science available to EPA, some states have been working for several years with a more stringent regulatory standard or advisory concentration than EPA's old and new version:

AZ: 14 ug/L

CA: 6 ug/L

MA: 2 ug/L

MD: 1 ug/L

NM: 1 ug/L

NY: 5 ug/L (but 18 ug/L before public notification)

[Note: The numbers above are from a blend of 2005 and 2009 EPA data; check with your state to see what concentration it is currently using, if different from EPA's.]

From 2001 to 2005, EPA required that 3,865 water utilities in the US, each of which serves 10,000 or more people, test for perchlorate in the water provided to customers. Thirty-one of the utilities had an average concentration that was the same as or higher than the new advisory concentration of 15 ug/L. These were among 160 utilities, in 26 states and 2 territories, that had at least one reading above 4 ug/L, which is the lowest concentration that can be measured by EPA's approved method. Other states with a threshold lower than 4 ug/L are using testing methods that are reportedly valid, but not yet EPA-approved. If a new standard is eventually set at a concentration in the range of 1-2 ug/L, which is still 10-20 times higher than recommended by some health advocates, water from these utilities will also be a concern.

EPA testing results[4] (and other perchlorate information, including the Jan. 8, 2009, announcement); under Q&A, click on "How frequently is perchlorate found in drinking water?" about 2/3 of the way down.

There are several ways to identify the concentration of perchlorate in the drinking water of any of the 3,865 utilities that serve your audience members. The easiest may be to ask utilities for their annual "Consumer Confidence Report," which documents contaminants found in their water supply. It would be best to get all years from 2001 to 2007 (the latest issued, in mid-2008). Since utilities that serve fewer than 10,000 people can sometimes have a more difficult time meeting water quality standards, due to fewer resources, it'll also pay to check their Consumer Confidence Reports. Some of them may have voluntarily tested for perchlorate. An added bonus of this process is that, even if there are no immediate perchlorate concerns, you may unveil other drinking water problems.

Another way to begin to identify possible problem areas is to review information on known contaminated sites. You can then check on Consumer Confidence Reports, or other state or utility data, near those sites. Basic information about 236 federal and industrial manufacturers or users of perchlorate, and known releases of perchlorate, is available through EPA:

Another option is to work through a large, complex spreadsheet provided by EPA. You need to know how to work with Excel Pivot Tables, and be able to download and work with large zip files. If you're part way there with this, and need a little extra guidance, you might ask the media contact at EWG to link you up with a staff member who has worked with this data before.